The present invention relates generally to tray handling equipment for removing filled or partially filled trays from a mail sorter and replenishing the mail sorter with empty trays. The invention is particularly useful with flats mail sorters.
Flats mail sorters are known and are commercially available. Flats mail sorters sort flat mail, such as magazines, large envelopes and the like, and discharge the sorted mail into trays. Each of these trays may be devoted to a particular mail distribution center, carrier route, delivery point, zip code or the like. Typically, a mail sortation system includes one or more rows of multiple sorter units. Examples of flats mail sorters include models FSM100 and TOPS 2000, marketed in the United States by Rapistan Systems of Atecs Mannesmann AG. As the mail is sorted, the filled or partially filled trays must be removed from the location at the particular sorter and replaced with an empty tray. Occasionally, there is also a requirement that a sweep operation be performed, whereby all of the trays are removed from their respective locations, even if the trays are only partially filled. Empty trays are then stocked at each of the sorters.
The removal of filled or partially filled trays and replacement with empty trays is traditionally performed manually. One or more operators must manually remove the at least partially filled tray from each of the multiple sorters and replace it with an empty tray, such that the sorter may continue the sortation process. Accordingly, the operation of the sorting machines is quite labor intensive.
A system has been proposed which includes a shuttle cart that travels underneath the chutes of the mail sorter units and carries multiple trays thereon. The trays are hoisted up into position beneath an appropriate sorter unit and locked or clamped in position at the sorter unit, so the cart may move to another sorter unit. Once filled, the trays are grabbed and moved down onto a shuttle cart for transporting the tray from the sorter unit. Such a system requires a rigid tray that is strong enough to withstand the clamping of the tray during the filling process. The system is also slow to provide empty trays to the sorter units and to move the full trays away from the sorter units.
Therefore, it is desirable to automate the manual processes of providing an empty tray to a sorter and/or removing an at least partially filled tray from the sorter.
The present invention is intended to provide an automatic tray handling system for an article sortation system, such as a flats mail sortation system. The tray handling system is operable to remove at least partially filled trays from multiple sorter units and provide empty trays to the sorter units for filling with articles, such as mail and the like.
According to one aspect of the present invention, an automatic tray handling system for use with an article sorter includes at least one conveying surface and a plurality of tray moving devices. The article sorter includes a plurality of tray support areas for positioning a tray while the tray is being filled with sorted articles. The conveying surface is operable to convey empty trays and/or at least partially filled trays generally adjacent to the tray support areas. The tray moving devices are operable to move empty trays from the conveying surface to the tray support areas and to move at least partially filled trays from the tray support areas to the conveying surface.
In one form, the tray handling system is operable to convey empty trays in a generally continuous loop about the conveying surfaces until the empty trays are selected and filled at a sorter unit. The article sorter system may include a pair of rows of sorter units. Preferably, the conveying surfaces include a first and second conveying surface along each side of the article sorter system. Empty trays may be removed from the first conveying surface and, after filling at the sorter unit, may be inducted back onto the first conveying surface and conveyed to a labeling station at a discharge end of the tray handling system. Preferably, the first conveying surface is positioned above the second conveying surface. A vertical tray moving device may be positioned at a downstream end of the first conveying surface to remove empty trays from the first conveying surface and move the trays down onto the second conveying surface so the empty trays may continue to cycle along the conveying surfaces. A connecting conveyor may connect a downstream end of the second conveying surfaces to an upstream end of the first conveying surfaces to complete the loop.
In another form, the conveying surface comprises an empty tray conveyor and a filled tray conveyor. Empty trays are removed from the empty tray conveyor and moved to the sorter unit for filling. The filled trays or at least partially filled trays are then moved from the sorter unit to the filled tray conveyor for conveyance to a downstream operation, such as a labeling station at a discharge end of the tray handling system.
Preferably, the filled or partially filled trays are electronically identified and tracked as they proceed along the conveying surface. A labeling station may be positioned at a downstream end of the conveying surface and may be operable to create and affix a label to each filled tray as it arrives at the labeling station. The labeling station may also include a scanner to verify that the label affixed to each tray is appropriate for the electronic identification of that particular tray.
According to another aspect of the present invention, a method for handling trays is provided for use with an article sorter which includes a plurality of sorter units and a plurality of corresponding tray support areas for positioning a tray while the tray is being filled with sorted articles. The method includes providing at least one conveying surface along the sorter units and conveying empty trays along the conveying surface. The method further includes moving empty trays from the conveying surface to a tray support area and at least partially filling the empty tray at the tray support area. The partially filled trays are then moved onto the conveying surface and may then be conveyed therealong to a downstream operation, such as a labeling station.
Preferably, empty and filled trays are conveyed along a first conveying surface, while empty trays are conveyed along a second conveying surface. The empty trays may be moved from a downstream end of the first conveying surface onto an upstream end of the second conveying surface. The empty trays are than movable along the second tray conveying surface to return toward an upstream end of the first conveying surface.
In one form, the article sorter includes a pair of rows of sorter units along opposite sides of the article sorter. Preferably, the method provides for moving trays in a generally continuous loop around first and second conveying surfaces at both sides of the article sorter. More particularly, the method may provide for moving empty trays at a downstream end of the second conveying surface at a first side of the article sorter onto an upstream end of the first conveying surface at the second side of the article sorter. The empty trays are then conveyed along the first conveying surface along the second side and then moved from a downstream end thereof to an upstream end of the second conveying surface at the second side of the article sorter. The empty trays are then conveyed along the second conveying surface at the second side to a downstream end thereof. The empty trays are then moved from the downstream end of the second conveying surface at the second side to an upstream end of the first conveying surface at the first side of the article sorter. The empty trays are then conveyed along the first conveying surface at the first side of the article sorter and moved from a downstream end thereof to an upstream end of the second conveying surface at the first side. The empty trays are then conveyed along the second conveying surface at the first side to the downstream end thereof, thereby completing the continuous loop.
Preferably, the first conveying surface is positioned generally above the second conveying surface. The empty trays are moved from the downstream end of the first conveying surface to the upstream end of the second conveying surface via a vertical tray moving device. Also, the empty trays are moved from the downstream end of the second conveying surface to the upstream end of the first conveying surface via a return device, such as a connecting conveyor surface, such as an incline ramp belt conveyor.
Therefore, the present invention provides an automatic tray handling system for an article sorter which is operable to remove at least partially filled trays from a sorter unit along the article sorter and replenish the sorter unit with an empty tray. The present invention provides movement of empty trays in a generally continuous loop about the article sortation system until the empty trays are selected and filled by the sorter units. Accordingly,the present invention substantially reduces the manual labor required to exchange filled trays with empty trays at an article sortation system, such as a flats mail sorter or the like.